The invention relates to a device for producing high pressure in a fluid. It comprises a piston which is movable in a cylinder, and a valve, both preferably of miniaturised construction. The invention further relates to a high pressure atomiser which contains this device, and the use thereof, preferably for medicinal purposes.
One aim of the invention is to enable a device of this kind and the atomiser containing the device to be made simpler in design and cheaper to produce and suited to its function.
In liquid chromatography (HPLC), for example, generally relatively small quantities of liquid are conveyed at high pressure through the separating column. Moreover, in medicinal aerosol therapy, aerosols are obtained, by atomising or nebulising liquid drugs for treating diseases of the respiratory tract in humans or for treating asthmatic conditions. Here again, a high pressure is required in a, generally relatively small, quantity of fluid in order to produce the small droplet size needed for the aerosol. In the metered dose inhaler according to U.S. Pat. No. 5,497,944, (the entire contents of which are incorporated herein by reference) a predetermined volume of a fluid is sprayed through a nozzle with a small aperture under a pressure of between 5 and 40 MPa (about 50 to 400 bar) to produce an aerosol. The present invention is particularly applicable to such metered dose inhalers and similar devices.